Synapses Flashcards
Name the part of a nerve cell that carries a message to the cell body.
Dendrites
Name the part of the nerve cell that contains the nucleus.
Cell body
Name the part of the nerve cell that carries a message away from the cell body.
Axon
Name the sheath that surrounds the axon.
myelin
What is the purpose of the myelin sheath?
Increases the speed of impulse conduction
Why are responses to stimuli in the first 2 years of life not as rapid or co-ordinated as those of an adult?
Myelination in not complete
Name the cells that produce the myelin sheath.
Glial Cells
Name the cells that support neurons.
Glial Cells
Multiple Sclerosis is a disease that destoys the myelin sheath, what is the result for the person?
Loss of co-ordination
What are neurotransmitters stored in at the presynaptic neuron?
vesicles
What is the name of the gap between an axon of one cell and the dendrite of another cell?
synaptic cleft
What does an electrical impulse arriving at the end of an axon cause to happen?
Vesicles release the neurotransmitter into the synaptic cleft
How do neurotransmitters move from the axon ending to the postsynaptic neuron?
diffusion
What remove neurotransmitters from the receptors?
enzymes
Why is it important that enzymes are removed from the receptor?
Prevents continuous stimulation of postsynaptic neurons
What determines whether a signal is excitatory or ionhibitory?
The receptor
What name is given to the minimum number of neurotransmitters that must attach to a receptor to transmit an impulse?
Threshold
If threshold is not reached, what happens to the impulse?
It is filtered out as unimportant
What term is used to describe a number of weak stimuli combining in order to reach threshold?
summation
In which type of neural pathway does summation take place?
Converging
Name the neurotransmitters that stimulate neurons involved in reducing the intensity of pain.
Endorphins
Name 3 things that can increase endorphin production.
severe injury, exercise, stress, sex and certain foods
Name the neurotransmitters that induce feelings of pleasure?
dopamine
On which part of the brain does dopamine activate and why?
reward pathway to reinforce a particular behaviour
Name the part of the brain that has neurons which secrete and respond to dopamine.
The reward pathway
If a drug is described as an agonist, what does this mean?
they bind to and stimulate specific receptors mimicking the neurotransmitter
If a drug is described as an antagonist, what does this mean?
they bind to specific receptors and block the action of the neurotransmitter
Other than agonists and antagonists, state 2 ways drugs can affect neurotransmitters at the synapse.
- inhibit enzymes that break the neurotransmitters down 2. inhibit reuptake of the neurotransmitter
Which type of drug causes drug addiction by sensitisation?
antagonists
How do antagonist drugs affect the number and sensitivity of the receptors?
increase the number and sensitivity
Which type of drug causes drug tolerance due to desensitisation?
agonists
How do agonist drugs affect the number and sensitivity of the receptors?
decrease the number and sensitivity
What effect can the use of recreational drugs have on an individual?
change their mood, perception and behaviour
What do we call drugs that imitate the natural neurotransmitter?
agonists
What do we call drugs that block the receptors and stop the natural neurotransmitter from binding?
Antagonists
Give an example of a behaviour that is rewarded by dopamine.
eating when hungry, sex
